This invention relates to a cotton harvester and more particularly relates to an improved picker bar assembly having a cam follower arm with an extension that projects downwardly into the drum head.
In conventional cotton harvesters of the type shown, for example, in U.S. Pat. Nos. 3,245,210 and 4,133,166 to Hubbard, a vertically disposed picker bar is journalled in the drum head of an upright cotton picking unit. Currently available picker bars are fabricated from an aluminum extrusion to reduce mass. The upper end of the bar is keyed and press fitted to a cast cam follower arm, which includes a follower seated in a cam track to properly orient the bar during harvesting. The bar supports a plurality of spindles which are driven by a spindle drive shaft rotatably supported within the bar, in part by a bearing contained within the upper portion of the bar.
A principal drawback of the typical prior art design is that the aluminum bar is one of the weakest members of the harvesting unit, and bending or fracturing of the bar or loosening of the cam follower arm can occur when the bar is subjected to abnormally high loading. The size and therefore the capacity of the spindle drive shaft bearing is limited in the prior art construction by the inner diameter of the aluminum bar.
It is therefore an object of the present invention to provide an improved cotton picker bar. It is another object to provide such a bar which overcomes the above-mentioned disadvantages of previously available picker bars.
It is a further object of the present invention to provide a cotton picker bar which is more resistant to bending and/or fracturing than at least most previously available bars. It is another object to provide such a bar wherein excess loads which would otherwise damage the bar are instead absorbed by the cam arm and drum head.
It is yet another object of the invention to provide a cotton picker bar assembly having an improved connection between the cam follower arm and the picker bar to increase strength of the bar and to resist loosening of the cam follower arm even when the bar is subjected to abnormally high loading. It is still a further object of the invention to provide an improved cotton picker bar assembly wherein the size of the spindle drive shaft bearing is not limited by the inner diameter of the aluminum bar.
The picker bar assembly of the present invention is constructed such that the cam follower arm has an extended area of press fit over the upper end of the picker bar. The extension of the arm projects downwardly into the drum head and provides a picker bar journal. Any abnormally high load which would otherwise bend or deflect the bar is transmitted into the head and arm. The extension permits placement of a high capacity spindle drive shaft bearing in the cast cam follower arm directly above the upper end of the bar. The extension also provides an increased length of press fit to resist loosening of the cam follower bar on the bar.
These and other objects, features and advantages of the present invention will become apparent to one skilled in the art from the description which follows and the accompanying drawings.